Sanitizer chemistry impacts growth and cross-contamination risk of Salmonella enterica serovar Typhimurium in the food service sanitation bucket system

Despite routine use of cloth-and-bucket (red bucket) systems with sanitizers for food contact surfaces in retail environments, limited evidence exists on their effectiveness. This study assessed Salmonella Typhimurium survival, growth, and cross-contamination risk in sanitizer bucket systems. Three cloth types (cotton, microfiber, non-woven) and four sanitizers (two quaternary ammonium-, one chlorine-, one acid and anionic surfactant-based) were tested. Samples were collected from five sources: contaminated boards, the bucket following pathogen exposure, sterile boards for cross-contamination assessment, the bucket at defined intervals, and the cloth at study completion. A quaternary ammonium-based sanitizer (QAC2) was most effective on contaminated Formica boards (3.67 ± 0.76 log 10 CFU/mL) and caused the least cross-contamination onto sterile boards (below the limit of detection, log 10 < 0.0458). Cotton left significantly (P < 0.05) more bacteria on contaminated boards (4.72 ± 0.40 log 10 CFU/mL) and caused the greatest contamination of sterile boards (1.86 ± 0.47 log 10 CFU/mL). Bacterial load within the bucket significantly increased after the cloth contacted each contaminated board (P < 0.05). Organic load addition decreased chlorine ppm and increased acid and anionic surfactant-based sanitizer pH, reducing efficacy (P < 0.05). These findings highlight critical gaps in current sanitization guidance and underscore the need for evidence-based sanitizer and cloth selection to mitigate cross-contamination risk in retail food environments.